ABSTRACT
Nuclear magnetic resonance (NMR) is a powerful analytical tech-
nique with application in materials science, biology, and medicine.
Nowadays NMR is an essential tool for the synthetic chemist as
well as the materials scientist, but it has made the connection
with the great public through imagiology wheremagnetic resonance
imaging (MRI) constitutes one of the most important methods of
in vivo observation of structure and functionality of a living body.
Foreseeing its great potential, the discovery and developments of
this technique were recognized as major scientific achievements
and have been rewarded with the attribution of several Nobel
Prizes to those responsible for the discovery and development of
the technique. It all started with the discovery of NMR in 1936
by Isidor Rabi while studying molecular beams (Rabi, 1937). Rabi
found that a molecular beam exposed to a static magnetic field and
submitted to radio waves can experience changes in the nuclear
spins direction in a quantized form following quantum mechanics
rules. For this discovery Rabiwas awarded theNobel Prize in Physics
in 1944. The extension of this technique to the study of liquids
and solids by Felix Bloch and Edward M. Purcell in 1944 when
they were trying to measure nuclear magnetic moments with higher
precision using liquids and solids (Bloch, 1946; Purcell, 1946)
granted them also the Nobel Prize in Physics that they shared in
1952. The first commercially available NMR spectrometer appeared
in 1953 and since then a huge development of this technique
took place. By 1970 pulsed methods were introduced in NMR and
rapidly replaced the continuous-wave (CW) excitation (CW NMR)
used up to then. The pulsed method, allied to the use of computer-
implemented fast Fourier techniques, allowed the study of much
more diluted samples and also much less abundant nuclear species.
These pulsed techniques opened the way to what is called today
2D NMR where complex sequences of radio-frequency (RF) pulses
generating 2D spectra are used. Richard R. Ernst, a prominent
researcher in this area, was awarded the Nobel Prize in Chemistry
“for his contributions to the development of the methodology
of high-resolution nuclear magnetic resonance” in 1991 (Ernst,
1976). Since then, multidimensional NMR has grown continuously
and in 2002 Kurt Wuthrich shared the Nobel Prize in Chemistry
“for his development of nuclear magnetic resonance spectroscopy
for determining the 3D structure of biological macromolecules in
solution” (Wuthrich, 1983). As pointed before one very important
development of the NMR technology that has reached the great
public is MRI, an imaging technique with unique capabilities in the
fields of anatomy and physiology, the relevance of this technique has
been recognized and two leading researchers were distinguished
in 2003, Paul C. Lauterbur and Sir Peter Mansfield were awarded
the Nobel Prize in Physiology or Medicine “for their discoveries
concerning magnetic resonance imaging.”
